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Topic: Micro 10-30rpm motor suggestions? (Read 6137 times)

Hi guys, I'm looking for a motor for my current project but know very little about them and would appreciate your thoughts and suggestions.

I can run from mains voltage, so supply isn't too much of a consideration in that I could use a Dc power supply to run a 12v motor (which I expect it will be) or anything else.

The main factors are:Slow rpm - 10-30rpm ish. Run continuously for up to 1-2 hours. Quiet... This is for a home display so it must be quiet! Small - but I understand what is small? Ultimately this is going to be fitted under a circular base, approx 250mm diameter. Whatever the motor height is will raise the base. So the smaller the better to fit under a 25cm dial base.

The datum you've forgotten is the torque required. This is for the Orrery project, right? I need to check the measurements this evening, but I think I have one in the junk stuff for future projects crate that I could send you.

The datum you've forgotten is the torque required. This is for the Orrery project, right? I need to check the measurements this evening, but I think I have one in the junk stuff for future projects crate that I could send you.

I'll get back to you this evening.

Yes, it's a great point and I can't give you a figure. Yes it is for the orrery and with everything running on bearings it should take a very very light finger push to move it around. I'd definitely be interested.

How about a microwave plate motor. I'm not sure but I think they are about 5 rpm which may be a bit slow but you may be able to gear it up. I find they are generally free as round this way they are left by the the roadside for the scrap man.

Take virtually any small DC motor and gear it way down using pulleys that fit O-rings, or timing belts if that works better. Have one or more indexing pulses on your disc or whatever that are connected to a simple microcontroller (these have now become ubiquitously referred to as "Arduino" noweadays, regardless of what silicon is behind the system). Use very simple PID to control the motor RPM. There may be some discrete circuit that would work, but with high powered silicon being virtually throw-away there's not much point to look elsewhere.

he RPM pickup could be as simple as a light-interrupting laser-printed encoder wheel or something you've drilled equally on a rotary table setup. Sounds complicated, I know, but the cost would likely be less than the stuff you've been looking at. I guess it depends how tightly controlled you need the RPMs as well. Maybe it would be sufficient to just run it at a fixed voltage you've determined makes the output the speed you want.

Hi guys, I'm looking for a motor for my current project but know very little about them and would appreciate your thoughts and suggestions.

I can run from mains voltage, so supply isn't too much of a consideration in that I could use a Dc power supply to run a 12v motor (which I expect it will be) or anything else.

The main factors are:Slow rpm - 10-30rpm ish. Run continuously for up to 1-2 hours. Quiet... This is for a home display so it must be quiet! Small - but I understand what is small? Ultimately this is going to be fitted under a circular base, approx 250mm diameter. Whatever the motor height is will raise the base. So the smaller the better to fit under a 25cm dial base.

Any help appreciated.

Have a look at microwave oven turntable motors. These are thin (circa 12-15 mm) and run at the right sort of speed range.

Have a look at an old 5.25 inch floppy drive spindle motor, or even a 3.5 inch one. The motors have the controller built in, I'm sure that they can be controlled digitally. They are pancake type motors and are around 1/2" thick.